Currently, rotating seal rings are used in applications such as in transmissions, particularly for preventing or substantially limiting fluid leakage and pressure loss from portions of the transmissions subject to high pressure conditions, such as the clutch packs, wherein pressure can be as high as 400 pounds per square inch (PSI). Generally, the known rotating seal rings for sealing transmission clutch packs are "wet seals", that is, both the high pressure and low pressure faces or sides thereof are exposed to or are in communication with a liquid such as a transmission oil or the like typically having lubricating properties. The rotating seal rings further often include at least one face or side that is positioned in opposing, face-to-face relation with a non-rotating surface of the transmission case for forming a sealed or substantially sealed condition therewith. The known rotating seal rings are typically made of a metal or hard polymer such as polyimide, and the opposing surfaces of the transmission case are typically metal, such as cast iron or the like.
A problem that can occur with the known rotating seal rings when subject to the above referenced high pressure conditions, is that they can be forced by the pressure against the non-rotating metal surface or surfaces of the transmission case without adequate lubrication therebetween, resulting in possible damage to the seal ring, and operational problems including excessive leakage and parasitic power losses, clutch slippage, and eventual failure of the associated clutch pack and/or the transmission. This problem is particularly acute at higher rotational speeds wherein higher temperatures are generated between the seal ring and the opposing surface or surfaces due to friction resulting from the inadequate lubrication.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.